Photographic light-sensitive materials using silver halide are more and more expanding in recent years and at present, a high-quality color image can be easily obtained. For example, in a system usually called a color photograph, photographing is performed using a color negative film and the image information recorded on the color negative film after development is optically printed on a color paper to obtain a color print. Recently, this process has advanced to a higher level so that a color lab as a large-scale centralized base for producing a large quantity of color prints in high efficiency or a so-called mini lab as a compact and simple printer processor installed at a shop is popularized, and as a result, anybody can easily enjoy color photographs.
The color photograph currently popularized has a principle of using color reproduction according to a subtractive color process. A general color negative film comprises a transparent support having provided thereon light-sensitive layers using silver halide emulsions as light-sensitive elements imparted with spectral sensitivity in blue, green and red regions, respectively, each light-sensitive layer containing in combination a so-called color coupler which forms a yellow, magenta or cyan dye as a hue to come to a complementary color. After imagewise exposure by photographing, the color negative film is developed in a color developer containing an aromatic primary amine developing agent. At this time, exposed silver halide grains are developed, namely, reduced by the developing agent and the oxidation product of the developing agent, which is simultaneously produced, causes coupling reaction with the above-described color coupler and thereby each dye is formed. Metal silver (developed silver) generated on development and unreacted silver halide are removed by bleaching and fixing, respectively, to obtain a dye image. Through the thus processed color negative film, a color printing paper as a color light-sensitive material comprising a reflective support having provided thereon light-sensitive layers each having the same combination of sensitive wavelength region with colored hue is optically exposed and then subjected similarly to color development, bleaching and fixing, and thereby a color print comprising a dye image reproducing the scene of an original can be obtained.
The above-described system is widely popularized at present, however, demands for further simplicity are more and more increasing. First, processing baths for performing color development, bleaching and fixing need be precisely controlled on the composition and the temperature and therefore, professional knowledge and skilled operation are required; second, the processing solutions contain materials restricted in the discharge in view of environmental conservation, such as a color developing agent and an iron chelate compound bleaching agent, and therefore, facilities for exclusive use are required in many cases for installing equipments such as a developing machine; and third, although the processing time is reduced by the technical development in recent years, time needs be spent on the above-described development processing and accordingly, the demand for rapid reproduction of a recording image cannot be satisfactorily met.
Under these circumstances, a large number of improved techniques have been proposed. In particular, in order to achieve simple and rapid development, various techniques using a so-called high silver chloride emulsion having a high silver iodide content have been proposed. By using a high silver chloride emulsion, the development rate is accelerated and at the same time, capability of reuse of the processing solution advantageously increases. Accordingly, the light-sensitive material for printing such as color printing paper which are predominantly used in recent years uses a high silver chloride emulsion.
As a technique of applying the advantage of rapid developability inherent to the high silver chloride emulsion to the light-sensitive material for photographing, U.S. Pat. Nos. 5,264,337, 5,292,632 and 5,310,635 and WO94/22054 disclose a technique of using a tabular, high silver chloride emulsion constituted by (100) faces in the light-sensitive material for photographing. By using the high silver chloride emulsion, high development rate can be achieved and at the same time, there is provided an advantage such that the light-sensitive material for photographing and the light-sensitive material for printing can be processed using the same processing solution.
However, as described in the above-described patent publications, various problems arise due to the development characteristics of the high silver chloride emulsion. First, if good granularity is intended to obtain, development of grains after initiation of development must be inhibited on the way, but since individual grains of the high silver chloride emulsion have high development rate, the development initiation time is liable to be uneven among the exposed grains and high-sensitive photographic response can hardly be obtained at the initiation stage of development. Second, if high developability of the high silver chloride emulsion is intended to use, graininess is readily worsened, accordingly, to achieve properties required for the photographic material for camera work, such as wide exposure latitude and excellent graininess, using the high silver chloride emulsion is highly difficult in view of technical point and this is not yet overcome by the techniques described in the above-described publications. Thus, a large number of principle problems are remaining in achieving a light-sensitive material for photographing using the high silver chloride emulsion.
Apart from these attempts, a technique of constructing a system not using a color developing agent and a bleaching agent which are used in the current color image formation system, thereby lightening the load on the environment and improving simplicity, has been reported. For example, IS & T's 48th Annual Conference Proceedings, page 180, discloses a system dispensable with the bleach-fixing bath which is indispensable in conventional color photographic processing, where a dye produced on development reaction is moved to a mordanting layer and then, the layer is peeled off to remove developed silver or unreacted silver halide. However, in the technique proposed here, development processing in a processing bath containing a color developing agent is still necessary and the environmental issue can be hardly overcome.
As a system not using a processing solution containing a color developing agent, a Pictrography system has been proposed by Fuji Photo Film Co., Ltd. In this system, a slight amount of water is fed to a light-sensitive material containing a base precursor, laminating it to an image-receiving material, and these are heated to cause development reaction. This system is advantageous in view of environmental issue because the above-described processing bath is not used. However, this system is intended to use in fixing the image formed to a dye fixing layer and viewing it as a dye image, and therefore, a system usable as a recording material for photographing has been demanded.